This invention relates to door latches of the type adapted to be mounted along the edge of a door which overlaps a frame and the side opposite the hinge, and more particularly to the type which draw the door forcibly against the frame. Pull-up latches of this type are disclosed in my U.S. Pat. Nos. 4,230,351, 4,556,244, 4,583,775, 4,693,503, 4,763,935 and 4,880,261.
In U.S Pat. No. 4,230,351, the output motion of the latching finger or pawl is a single angular motion, the last part of which in the opening sequence causes the latching finger to withdraw sufficiently to clear the frame or keeper. During latching, because the latching finger is rotating, it is sliding across the keeper while it is pulling up. The input is in the form of a single angular actuation of the handle.
U.S. Pat. Nos. 4,693,503 and 4,880,261 are similar in function to U.S. Pat. No. 4,230,351. The same comments apply to these, particularly with respect to the sliding action during latching.
In U.S. Pat. No. 4,556,244, the output motion of the latching finger consists first of a rotational motion to position it behind the frame, followed by a straight line pull-up. This is an obvious improvement over the above. The input is in the form of a single rotational actuation of the handle. It is noted, however, that if the handle is turned only partially, the latching finger is brought behind the frame, but no pull-up is achieved.
In U.S. Pat. No. 4,583,775, the input and output are identical to U.S. Pat. No. 4,556,244. The same comments apply to this as to U.S. Pat. No. 4,556,244.
Finally, in U.S. Pat. No. 4,763,935, the output motion of the latching finger consists of the more desirable positioning motion followed by a straight line pull-up. In this case, however, the input consists of two separate motions, a rotational motion about one axis, followed by a rotational motion about a second axis, both of which must be performed to fully latch the fastener.
My U.S. Pat. No. 4,655,489 is mentioned here merely as a reference. It shows another form of the push-release type of device incorporated in the present invention.